Module extension 

Extension DTypes, and interfaces for working with extension types.

File layout convention

Each vtable-backed concept Foo follows this module structure:

• vtable.rs — FooVTable (the non-object-safe trait users implement)
• plugin.rs — FooPlugin (registry trait for deserialization + blanket impl)
• typed.rs — Foo<V> (typed wrapper) + FooInner<V> + DynFoo (private)
• erased.rs — FooRef (erased ref + Display/Debug/PartialEq/Hash impls)
• matcher.rs — Matcher trait + blanket impl for V: FooVTable

Structs

ExtDType

A typed extension data type, parameterized by a concrete ExtVTable.

ExtDTypeRef

A type-erased extension dtype.

Traits

ExtDTypePlugin

Registry trait for ID-based deserialization of extension dtypes.

ExtVTable

The public API for defining new extension types.

Matcher

A trait for matching extension dtypes.

Type Aliases

ExtDTypePluginRef

Reference-counted pointer to an extension dtype plugin.

ExtId

A unique identifier for an extension type